I'm a proud owner of a used 328i, and I'm new to this forum. I didn't realize it at the time, but interior fan speed doesn't really adjust very well. Also when I turn off my interior fan, I can hear another fan (not the same one that cools down the car) keep running. It is as if the car is trying to suck in air, but it doesn't actually reach the interior because the interior fan is off. I plan to bring the car in for a check, but I was wondering if I can fix this problem myself. Has anyone experienced this problem?